1. Field of the Invention
The present invention relates to an image/audio reproducing apparatus for decoding/reproducing digitally compressed/coded image and audio data.
2. Description of the Prior Art
An image/audio reproducing apparatus for decoding/reproducing digitally compressed/coded image and audio data includes a system decoder for demultiplexing the multiplexed compressed/coded data into image data and audio data, a video decoder for decoding/reproducing the image data, and an audio decoder for decoding/reproducing the audio data.
FIG. 1 is a block diagram showing the arrangement of a conventional image/audio reproducing apparatus.
In the conventional image/audio reproducing apparatus, each of a system decoder 22, a video decoder 23, and an audio decoder 24 has an independent data memory. First, multiplexed compressed/coded data is loaded from a data storage unit 21 into a data memory (SBS memory) 25 of the system decoder 22. The system decoder 22 demultiplexes the data, and the demultiplexed image and audio data themselves are copied to the data memories (a VBS memory 26 and an ABS memory 27) of the video decoder 23 and audio decoder 24, respectively, so the data are transferred between the decoders. The video decoder 23 and audio decoder 24 sequentially load the data from the data memories 26 and 27, respectively, and decode the data.
Such a conventional image/audio reproducing apparatus is disclosed in Japanese Unexamined Patent Publication No. 7-153192.
In the above-described conventional apparatus, particularly, as the bit rate (the number of bits to be processed per second) of coded data rises, the load necessary for memory copy of data between the decoders increases to degrade the decoding performance of the reproducing apparatus.
Especially, when decoding is executed on the basis of software, the data processing capability become low, so real-time reproduction may be disabled. The data are not reproduced in real time (the original image/audio reproduction rate).
If real-time reproduction is disabled, decoding of appropriate frames must be omitted (time-lapse reproduction) in the image reproducing apparatus to synchronize the image and audio data. However, this generates a sense of incompatibility in viewing the image.